Butterflies (GAH they scare me)
Needles (doctor needles, not sewing needles. That'd be just plain ironic.)
Spiders (not the giant poison ones, those are cool-looking, like on TV or something, but the icky tiny ones that live in your bathroom o.o)
Insects (used to love them as a kid)
Rejection (yep..)
Airplanes (not heights, though. I LIKE HEIGHTS!! Planes are evil.)
Thinking about the universe, big bang, earth, and weird sciencey fiction crap like that.

I noticed that all the fears that exist have one main thing in common: death. People fear death for lots of reasons, like they don't wanna get bitten by a spider and die, fall off a cliff and drown, etc.